Thermosetting foams such as polyurethane foams are known to be effective caulking and sealant materials. Moreover, thermosetting polymeric foams have been packaged in aerosol containers. Aerosol containers provide a particularly facile means for dispensing a thermosetting polymer which upon release from the container valve machanism cures in open moist air. However, commercially available thermosetting resins which are packaged in aerosol containers have a tendency to clog due to the premature setting of the polymeric component in the interval valve passages of the container. This premature setting and clogging of the dispensing mechanism is believed to be due to the interaction of air and the thermosetting polymer in quite narrow valve passageways associated with the dispensing valve. Thus, the user may be faced with the difficult and complicated task of cleaning clogged valve passageways, or in the alternative, disposing of a partially filled container.
Polyurethane foams have many household uses such as sealing joints in woodwork, masonry and ceramics. The ease with which polyurethanes may be applied to a surface from an aerosol dispenser renders such products particularly well suited for do-it-yourself household use. Homeowners have a great interest today in sealing joints around windows, doors, wall masonry and the like to achieve energy conservation. Thus, it is important that effective caulkers or sealants be provided which can be conveniently applied without the recurrent problems of valve clogging which have been noted with known aerosol dispensed thermosetting resins.